Apparatus for manufacturing cellulose coated and impregnated fibrous tubes

ABSTRACT

Apparatus for the continuous manufacture of sausage casings and like tubular structures of the type in which a paper base is impregnated with cellulose derivative, comprises a tubular mandrel H to the upper part of which the paper strip G supplied from a roll G&lt;1&gt; is fed, a ring J surrounding the mandrel and serving to bring the strip into tubular form, a device such as nozzle K for applying a solution of a cellulose derivative, and a bath B for precipitating the cellulose derivative and into which the mandrel &lt;PICT:0475534/IV/1&gt; &lt;PICT:0475534/IV/2&gt; &lt;PICT:0475534/IV/3&gt; &lt;PICT:0475534/IV/4&gt; &lt;PICT:0475534/IV/5&gt; &lt;PICT:0475534/IV/6&gt; depends.  As an alternative, the coating device may be placed in the interior of the tube, the construction of the mandrel being suitably modified; and in a further alternative construction, the coating device is situated at a point in advance of the mandrel. In the construction shown in Figs. 1 and 4, the mandrel is supported by a bracket 1, and above the forming ring J there is provided a nozzle I for applying adhesive to the overlapping margins of the tubular paper strip.  This device which is shown in Fig. 6, consists of an adjustable deflector 19 for temporarily lifting the outer margin of the strip and an adhesive-applying nozzle 25 having its jet opposite a recess 18c on the face 18b across which the other margin of the strip moves; the nozzle is located in position by adjusting screws 28, 33.  At about the level of the ring J and coating nozzle K, the mandrel which is generally of tubular form, is fitted with a flanged sleeve 3, Fig. 10, so as to provide an internal support for the tube during the pasting and coating operations, the latter being performed by supplying coating solution to an annular nozzle 35, closely surrounding the tube and mandrel.  The mandrel at its lower part continues to support the coated tube until it reaches the precipitating bath, and in order that precipitation should take place within the tube the mandrel is fitted with inlet and outlet pipes 9, 10, Figs. 10 and 11, for the supply and withdrawal of the necessary liquid, the inlet pipe ending at a point well below the level of the bath, and the outlet pipe entering a cup 10a, the upper edge of which is slightly above the liquid of the external bath.  At this point lateral openings 6a in the mandrel permit the internal bath to have free access to the inner wall of the tube, so supporting the latter. The lower extremity of the mandrel consists of a blade 8, Fig. 11, which serves to flatten the tube so that it may pass round the roller B&lt;2&gt;, Fig. 1; from this point the flattened tube is led to the main driving roller D and thence to the washing, purifying &amp;c. baths C&lt;1&gt;, C&lt;2&gt;, &amp;c. As shown in Fig. 12, the mandrel may be equipped so as to permit the coating solution to be supplied to an annular nozzle 40 by means of which the interior of the tube is coated with solution; the nozzle is situated at the lower part of a tubular section 39 closely fitting the paper tube; opposite the nozzle and external to the tube, there may be provided a supporting ring 43, and below the nozzle and inside the tube a spreader 42.  In the case of apparatus in which the coating solution is applied to the strip previous to forming into a tube, the coated strip may first be passed through a drier, later the dried coating may be softened at the pasting point by a spray of solvent, and an external coating device may be included as in the form described above or alternatively, the drier may be omitted, and the external coating device replaced by a smoothing ring. Specifications 386,644 and 475,535 are referred to.

Jan. -11,1938. J. P. SMITH APPARAT S FOR MANUFACTURING CELLULOSH COATED AND IMPREGNATED FIBROUS TUBES Filed Jiine .s, 1955 5 Sheets-Sheet 1 J. P. SMITH .Jan. 11, 1933.

APPARATUS FOR MANUFACTURING CELLULOS E COATED AND IMPREGNATED FIBROUS TUBES Filed June 1935 5 Sheets-Sheet 2 ZM yJI w APPARATUS FOR MANUFACTURING cELLULosE COATED AND IMPREGNATE-JD FIBROUS TUBES F iled June s, 1955 A A '5 Sheets -Sheet 5 v I 24 \l A I. 5| U 1 Ja 25 J. P. SMITH APPARATUS FOR MANUFACTURING CELLULOSE COATED AND IMPREGNATED FIBROUS TUBES Jan. 11, 1938.

Filed June 8, 1935 5 Sheets-Sheet 4 W k /J an?! lhlflfffrffn v h 4 fl a i T m Mo J Jan. 11, 1938. V J. P. SMITH 2,105,273

APPARATUS FOR MANUFACTURING CELLULOSE COATED AND IMPREGNATED FIBROUS TUBES EiledJune 8, 1955 5 Sheets-Sheet 5 7 17 078 fimz JrrzaZ/z. J W

Patented Jan. 11, 1 93s W PAT FF CE '1 H i h h 2,1o5,27: 1 he v i .APPARATUSLFORMANUFACTURING CELLU- H LOSE COATED AND mrneom'ren ,F l-

BItQUS. TUBES r John'Paul Smith',"Chicago, 111., assignor to The i q i 3 a Visking Corporation, Chicago, 111., a corporation of Vir 'nia Anplifcationjune s, 1935; Serial No. 25,686 M e zrc aims. (01; 93-82) The present flinvention pertains to apparatus adapted to the economical production of a combined fibrous tube and a." matrix of cellulose, or

cellulose derivative, in which the fibrous tubeis 5 ti t .fj

i In accordance with the present inventiomin itspreferred practice, {a thinflong-fibred paper strip is curved about alongitudinal axis into the formoia tube with overlapping longitudinal l0, margins, the margins are pastedtogether, a

cellulose,]derivative coating is applied to thestrip, either before or afterit isforrned into a tube, and the formed andpasted tube is drawn through a regeneratingbath which efiects re.-

, 5 generation of the coating, that is, converts it into cellulose, or cellulose hydratd'andthe tube is then drawn through a purifying water bath, andthen, if desired, through a'water-bathcom taininga smallpercentage of ahygroscopic agent, 2 such asglycerine, The tube is then dried, prererably by passing it in inflatedcondition through a heatedfdrying chamber. 1} V I r jlifiiile the paper strip mayhave the cellulose derivative coating applied th'ereto prior to forming the strip into a tube andfpasting its overlapping, margins ,to'get'henwthe coating maybe 4 applied: after the tube has, been formed and pasted, In either event, it is preferred to, draw the coated tube continuously through a regenerating iiiediu m, or through a coagulating andregenerating medium, thence thr'ough a purifying bath, andfinally through a drier; 'and, in this operation, to form successive portipnsof the strip, progressivelm into tubular formv and efiect the pasting operation of the margins of the tube as the tube formation takes; place.

I have found, for example, that it is possible tofapply to a thin, bibulous'strip or paper of fragile character a viscose coating, and pass 40 the coated strip, formed into a tube, with the margins pasted together, through a coagulating and regenerating hath, thence through a purifyingbath, thence through abath containing a small percentageof glycerine, and finally through a drier, A thin, fragileistrip of paper, with such ajcoating applied may be subjected to acontinuous drawing; operation of the character stated, H j

My preferred practice, more specifically stated,

is ltodraw 'a strip of paper from a roll, subject it to curvature abouta longitudinal axis to form a tubewith overlapping longitudinalmargins,

applyjafstrip of viscose paste to the underlying margin, pass the J tubular formation through a forming ring which efiects pasting the margins,

thence through a viscose-coating ring which applies a coating; to the outer surface of the tube, pass the coated tube (over a depending mandrel) downwardly into ai eoagulating and regenerating bathfithence about a roller in the lower portion of, the bath, and thence upwardly and then through additional baths, one of which may be a puriiyihgbath and another a bath containing a smallpercentage of glycerine. The paper tube, now bearinga regenerated cellulose coating, may be passeddirectly through a drier ;"or, it maybe stored, on rolls, or otherwise, and passed from thestorage me'mberthrough a drier. Finally, the dried, coated tube may be cut into desired lengths. Suchtubesmay serve as containers for proved process and suitable apparatus for conveniently practicing the process, by a preferred method, and modifications thereof.

In the drawings Fig. 1 is a brolren side elevational view of improved apparatusadapted to the practice of the preferred process; Fig; 2 a broken sectional view, on an 'enlargedscale, taken as indicated at line 2 ofFig. 1, showingthe seam-pester in planj I Fig. 3, an "end 'elevational view of the apparatusfViewedfrom the right of the apparatus as shown inFig. 1, the coagulating and regenerating tankbeing shown in section, this, view showirig a battery of mandrelsfor enabling a plurality of tubes'to be formed in the sameapparatus; Fig. 4, a. skeleton vertical sectional view taken as indicated at line 4 ofFig. 3, showingone of the mandrels andattendantparts; Fig. 5, a planview l ofone' oi'the coating-applying rings, the view beingtaken as indicated at line 5 of Fig. 4; Fig. 6,

abroken upperperspective view illustrating one i of the seam pasters and its associated" mandrel, it being noted that an enlargement of the mandrel and a forming ring encircling said enlargement appear'at thelower portion of the figure;

Fig. '7,a broken vertical sectional view, illusv hating the application of a strip of paste to the underlying margin of the tubular paper member, the lower portion of the figure showing the man ner in which theforming-ri'ng compresses the seam in the pasting operation; Fig. 8, ahorizontal section taken as indicated'at line 8 of Fig. 7; Fig. 9, a sectional viewof the pasted tube; Fig. 10, a broken vertical sectional view illustrating the paper 'tube undergoing the application of an external coating, this view showingalso the pipes whichpass downwardlythrough the mandrel and serve to maintain a constantly renewedinternal bath within the paper tube; Fig. 11, a similar seetional view taken at a lower point'and showing the relation of the internal bath to the external bath, and showing also an internal tube-flattening member forming an extension of the mandrel, from which the tube is delivered in substantially flattened condition to the roller near the bottom of the bath (see Fig. .3) Fig. 12, a broken vertical sectional view illustrating a modification, in which provision is made for applying an internal coating to the paper tube; Fig. 13, a view illustrating a modification of the process, in which a coating is applied to one surface of a flat strip, the strip is then passed through a drier (without eifecting regeneration), the coated strip is then formed into a tube and sprayed with a solvent to soften the coating, the margins are pasted by passing through a forming-ring, and the tube is then in condition to be drawn through the regenerating bath; and Fig. 14, a view illustrating another modification of the process, in which a fiat strip is coated, is then formed into a tube without being subjected'to a drying operation, the tube is pasted, and the tube is then in condition to be passed through the coagulating and regenerating bath. H 7

Referring to the apparatus illustrated in Figs. 1-11, and describing said apparatus in appropriate terms with reference to the application of a viscose coating, practiced in accordance with the preferred method, A' designates a suitable frame which is provided with a standard A adapted to'support mandrels; B, a tank containing a coagulating and regenerating bath B, said tank having mounted in its lower portion a roller 13 about which the regenerated, or partially regenerated, coated tubes may pass as they leave the mandrels; C, C and C a series of baths which may serve, in the order named, for complete ing the regeneration, for purifying the regenerated coated tubing, and for introducing a small percentage of glycerine, for example, into the coated fabric; D, a roller disposed above the rear portion of the tank B; E, a series of rollers mounted on a portion of A of the frame at acousiderable distance above thetanks, 0,0 and C; F, rollers mounted in the lower portions of the tanks just mentioned; G, a fibrous strip undergoing transformation into a cellulose-coated tube, the tube passing from the mandrel about the roller B thence about the roller D, and then threaded about the rollers E and F in the manner illustrated in Fig. 1; H, a series of mandrels, shown as three in number (Fig. 3), suspended from the upper portion of the standard A and depending into the bath B; I, a seam-paster associated with each mandrel, the paster having connected therewith a supply pipe I, equipped with a strainer I and with a pump I J, a forming-ring associated with each mandrel and serving to complete the pasting; K, a coating applying ring associated with each mandrel and receiving a viscose supply through pipes K (Figs. 4 and 5), these pipes being equipped with strainers K and pumps K and L, (Fig.1) a main drive-shaft driven from any suitable source (not shown) serving to actuate shafts L, L and LP, the shaft L serving, through the medium of a gear-ratio-changer L1, to actuate a shaft L from which the shafts which actuate the pumps I and K are driven; the shaft L serving to actuate the roller D; and the shaft L serving to actuate'the rollers E. i

It will be understood that the rollers D and E are thus geared together sothat they operate at the proper speed to feedtlfe tubes through the apparatus; also, that the pumps I and K are so actuated as to positively deliver measured quantities of viscose to the seam-paster I and the coating-applying device K.

In applying a viscose coating to a paper tube,

I have found that one may employ a so-called viscose solution of the same character, composition, viscosity, etc. as is now commonly employed in the manufacture of extruded regenerated cellulose tubes. While commonly known as viscose solution, it is, perhaps, more properly defined as an aqueous dispersion of cellulose-sodium-xanthate; and, perhaps, there may be some free cellulose in the'dispersion. Reference to other cellulose derivatives will be made later.

The frame A may be of any suitable construction. The tanks employed may be of any suitable construction, and may be made of non-corrosive materials, or may have non-corrosive linings. The rollers, pipes, etc., may be composed of material which will withstand corrosive action.

A description of one of the mandrels H and attendant parts, as preferably constructed, will now be given. The standard A carries suitable brackets I from which the mandrels are suspended. Each mandrel preferably comprises a mandrel pipe 2 depending from a bracket I; a larger pipe-section 3 secured on the lower end portions of the pipe 2 and coacting with the forming-ring J and the coating-applying device K, as shown in Fig. 10; a coupling 4 secured to the lower extremity of the pipe 2, a little below the lower end of the enlarged pipe-section 3; a tubular mandrel-section 5 secured to and depending from the coupling 4, the member 5 being provided with external rings, or flanges, 5 with which the inner surface of the paper tube contacts as the tube descends into the bath; a smaller diameter tubular section 6 secured to and depending from the lower end of the section 5, as shown in Fig. 11, the section 6 being provided with lateral openings 6" which permit the internal bath, designated 1, to form a support for the inner wall of the paper tube; and an internal tube-fiattening'device 8 depending from the lower end of the pipe-section 6, the widened lower extremity of the member 8 being in position to permit the flattened tube to pass therefrom onto the lower roller B, as shown in Fig. 3.

Housed within each mandrel H is an internal bath-supply pipe 9 and a return suction-pipe ID, the lower end of the latter extending into an overflow-cup l0 (Fig. 11) which is supported on a bracket ll mounted internally in the lower portion of the pipe-section 6. The upper edge of the cup Ill is'preferably so located that the level of the internal bath 1 will be slightly above the level of the external bath B, as shown in Fig. 11. Liquid overflowing into the cup H) may be exhausted through the pipe 18 by any suitable exhaust device (not shown).

The pipe 9 (Fig. 10) comprises two sections which are detachably connected with the coupling 4, these sections being in communication with each other through a bore l2 extending vertically through the coupling. The coupling 4 is for convenience, a two-part coupling, the parts being connected by bolts 4. The lower end of the internal bath supply pipe 9 terminates some distance above the lower end of the tube-expander 8. As shown, the paper tube G becomes constricted or flattened as the tube approaches the roller B and finally the tube is sealed as it passes about the roller B It will be understood.

accordingly, that the internal bath '1 fills the paper tube from the point where it passes about the roller to the level shown in Fig. 11.

The internal bath pipes 9 and I0 enter the mandrel through its upper end. These pipes may be supported in any suitable manner (not shown),

by the mounting I3.

The seam-paster I be :unde rsto o d from Figs; 6-8. -,"-The' mandrel H:carries a "bearings, plate l8 whichis securedtothe mandrel byfscrews 18 This plate has =ari-enlargeme1it which .is

' providedwith an. outwardly presented face [8 crossedwby a groove |8.'2 The underlying margin of the paper strip G is :adapted to bear ,on the faceulB as the-strip is drawn. downwardly: Car-w Iried by the: enlargement mentioned'is a small vertical Iguide-member IQhaving a slottedhorizontalfshank'resting on the upper wallof the enlargement and adjustably secured imposition tical guide 13 wliich; is disposedlin an oblique, plane. w

The paperstrip I passed about-guiderjrods zmll and 22 (Fig. 1):

located a considerable distance, preferably frm- *feet to feet above the upper end of themandrel ,The paper strip is moderately tensionecl in .its passage about the guides mentioned, and: is f suspended in such manner that the paper maybe caused to"assume tubular :form without 'objectionable strain asthepaperpasssdownwardly. overthemandrel.- In Fig. 8,.the underlying lata eral margin of the paper strip isdesignated 23,;1 and the overlying margin is designated 2491!? will be seen that the margin fl is guided by the member) and held away from the margin 23 while the .band or strip of paste, is beingapplied to the margin. 23.

Thezp'aste-applying device comprises a'jnozzle 25,1forming a terminal for the supply-pipe I.

As shown inFig. 2, a hose-connection may be introduced in theline I to permitlfreedorn'of [movement in adjusting the nozzle. 1 The section 'otthepipe I" which carries the-nozzle is adjustably mounted ina block 21 which, in turn,"

isadjustably carried by a screw 28 which has threaded connection with a block 29. The block a 29, in turn,is adjustably connected-witha. block 30 havinga-shank connected 'with'a nut-equipped threaded" stud 3| which formsthe upturned ex- ,tremity of thebracket ISL; The connections be tweenthe'blockspfl and 30 areshown as comprising al guide-pin 32 andan adjustIngscreW 33.

The block 21 is-a two-part block, the upper section serving to clamp the pipe I to the lower,

section. Aclamping'screw' ll accomplishes the purposeJ J Y The supporting 'meansfor the nozzleis de i signed to permituniversal adjustment, and also j permit thenozzle to be withdrawn from operative position, when desired? Any suitable means for accomplishing this purpose maybe employed.

As wiH be understood from Figs. '7 and 8, the nozzle tipis provided with a smallhorizontal slot 25 whichisadapted to apply'a narrow band of paste to the underlying margin 23 of the paper I 1 before the" margins are brought into overlapped 70.

position. This slot-like orifice preferably is located opposite ther'ecess l8 of-the bearing-plate 18,. thus allowing a certain flexibility at this point. Asthe tubular strip passes downwardly to the.:.forming ring J, the overlap. is completed;

and in passing between'theforming ringu and dis taken fromra roll G5. and

lappedmargins are ironed together and the pasting of the seam is completed. ,The ring J preferably has its bore flaring somewhat at the upper and lower edges as indicated at 34.

- The paper tube, inits. completely pa sted con dition, is shownin Eig t). a t i i As shown in Fig. 10, .thecoating-applying device K preferably comprises an annular member 35 carried bythe bracket, I'Land agcompanion the enlarged section3 of the mandrel, theoverannular member 36 detachably mounted on the member 35. These ring-membersare formed to provide between them an annular viscose-chamber 37; and' the members are so formedas to provide between their inner edges an annular dischargeorifice 38., The parts are of. suitable material to withstand corrosiveaction. ,The pasted ,paper tube passes downwardly through the coating-applying device K, where an external coating of a cellulose derivative is applied to the tube. Reference hasheretofore beenymade to the pipes Kf (Fig, 5) through which the cellulose derivative is supplied to the chamber. The

coating material, preferably viscose, is pumped in measured quantity into the chamber 3'! and v forced through the annular'orifice, thus insuring a substantially, uniform. coating, Preferably,

also, theipaste supplied to the seam paster is viscose,

The papertube is progressively formed, as de: scribed, and is progressively passed through the regenerating bathB' and then through the subsequent baths, and finally,by continuous move-,

, ment,if desired, througha drier. t

In Fig. 3, the descent of aformed tube G into, the bath B is illustrated in the left-hand portion of the figure; and in Figpll, the relativelevels of the internal bath 1 and the external bath B',

as preferablymaintained,.are illustrated. 'It has been found desirable to maintain ,a supporting llquidcolumn within the paper tube; and pref- .erably such liquid column is a regenerating fluid,

or; in the case of viscose, a fluid containing both coagulating and regeneratingagents, ,,The,.in'-

.ternal bath, as wellas the externalbath, tends to permeate the paper and coagulate and regenerate the viscose.

Where the cellulose derivative ernploy ed cosegit is preferredto coagulate and partially regenerate the viscose in: the bath B. ;Any gases evolved outside the paper. tube will escape freely to the atmosphere; Such gases as may be evolved. within the paper tube areexhaustedthrough pipe HLthat is, through the initial end of the tubular mandrel. {In manufacturing a tube-:from thin paper in accordance with the process, it is preferred to use a coagulating and regenerating bath comprising about 16% to 18% ammonium su1 phate and about 2 to 4% sulphuric acid, in water. It has been found that such'a bath. while giving fairly rapid regeneration in the tank B;

avoids any violent evolution ofgases, andthus tends to the production of a uniformregenerated coating. i a

The temperature of the bath B"may con veniently be about 30- to 35? C.. If a higher tern perature be employed, the aciditymay be lowered somewhat. A bath of the character specified above works very well in dealing with paper having. a thicknessof, say, about .002: .Where a stronger fabric is employed, it may become desir 'able toincrease theacidity of the bath. It is possible, forexample, to obtain substantially complete regeneration within thewlbath B by; em-.

ploying an acidity of from about 5% to about 75 11% sulphuric acid, depending upon the temperature of the bath, the thickness of the coat, the rate of drawing, etc.

As known in the art, other coagulants and other acids may be employed in lieu of ammonium sulphate and sulphuric acid.

Referring to Fig. 10, the relation of the mandrel-section 3 to the forming-ring J and the coating-ring K is important. Thus, the mandrelsection 3 is reduced to provide clearance 3* between the mandrel and the paper tube G, except that bearing flanges 323, and 3 are left on 'the exterior of the mandrel. The flange 3' is slightly above the forming-ring J; the flange 3 is slightly above the coating-applying ring K; and,the'fiange 3 (a wider flange) underlies the annular orifice 38. The purpose is to avoid binding action on the paper tube and prevent opening the seam. Preferably, it will be noted, the clearends: 3 extends through the forming-ring, so that while pressure is applied to the exterior side of the seam, no binding against the mandrel will occur. In other words the tautness of the paper will sufiice, as opposed to the forming-ring pressure.

In a modification illustrated in Fig. 12, provision is made for applying an internal coating to the paper tube, designated G after it has been formed and its longitudinal margins have been pasted together. In this case the mandrel, designated H, is of modified form. It has an enlarged tubular portion 39, the lower end of which supports an internal coating-applying device, designated K This device is provided with an outwardly directed annular orifice 40 through which viscose is applied to the inner surface of the paper tube. A downward extension of the mandrel from the device K is in the form of a tubular member 4| which supports a spreader, 42 which serves to even or make more uniform the internal coating. If desired, an external ring 43 may be opposed to the internal coating-applying device K An internal bath may be supplied through a descending pipe 44 and a return pipe 45, corresponding with the pipes 9 and I shown in Fig. 11. Thus, the internally coated tube may be subjected to the action of an internal bath as well as an external bath. If desired, both internal and external coatings of a cellulose derivative may be applied to the paper tube. In the reaction which occurs during the passage of the tube through the bath, the viscose paste in the seam is also coagulated and regenerated. Thus, the tube becomes virtually an integral tube, the joint being effectively sealed by the regenerated cellulose.

In the modification shown in Fig. 12, viscose is supplied to the coating-applying device K through an internal pipe 46.

In the modificationshown in Fig. 13, the paper strip and the tube formed therefrom are designated G. In this case, a coating of viscose is applied to one surface of the strip at the point L, and the coated strip then passesthrough a drier M, thence about a roller N, and thence downwardly about a mandrel similar to the mandrel H heretofore described. A spray of solvent for the viscose is applied at 0 to the underlying margin of the strip to soften the viscose. The

tubular strip then passes through a forming ring J where the pasting is effected, and thence through a coating device K if desired. At this point,- a-very thin-secondeoating of viscose may be applied, if desired. The coated. tube then passes downwardly through the bath -B-- heretofore described, and the tube .then passes through the subsequent baths in the manner already described.

In the modification shown in Fig. 14, the paper strip and tube are designated G. In this case, a. viscose coating is applied and the paper is formed into tubular form while the viscose is still wet. The viscose coating is applied at L, the coated strip then passes about a roller N, thence downwardly about the mandrel and through a forming-ring J and thence through a smoothing-rin Q. where the coating is rendered more uniform and where additional viscose may be applied, if desired. The tube then.

continues downwardly through the bath B, and thence through the subsequent baths, as described above inconnection with the preferred procedure. I

If desired, the previously described coating-applying device K may have substituted therefor the coating-applying device Q.

It is preferred, in the manufacture of a coated tube which will have an extensive use in providing containers for meats, large diameter sausage-compositions, fruits, 'etc., to employ a very thin paper produced from long fibres. Papers well known on the market, such as Japanesepapers known as yoshino paper, rice paper, and the like, are well adaptedto the purpose. The papers which it is preferred to use are extremely attenuated and porous, however, being commonly of a thickness varying perhaps from .001 to.

.0025. While it is not desired to limit the invention unnecessarily, it may be said that these very thinpapers can be employed in the improved process and produce very desirable tough, strong regenerated-viscose-coated tubes well adapted for use in situations requiring much strength, coupled with. semi-transparency, ,or translucency.

It will be understood, however, that since the tubing must be drawn at great length through the coagulating and regenerating bath, thence through the subsequent baths, and finally through a drier, if it be desired to include the latter step in the continuous process, it is essential that precautions be taken to prevent injury to the paper. The manner in which the paper isled from the roll G in Fig. 1 and gradually brought into tubular form in practically free condition in descending to the mandrel contributes to the success of the process. Theapplication of the viscose coating to the paper tubing some distance above the bath B gives time for permeation and the forming of a matrix to occur and permits a certain tempering of the coated tubing before the tube enters the coagulating and regenerating bath. This is believed to contribute to the successful drawing of the tubing through the baths. When the coated tubing enters the bath B, the coagulation occurs almost instantly, and the regeneration proceeds fairly rapidly and is to a substantial extent accomplished before the paper passes about the roll 1? in the bottom of the bath B. As indicated above, any internal gases developed during the passage of the tube-through the bath B will be exhausted through the suction pipe 10. I

A suitable so-called viscose solution, adapted for use in the process, may be prepared in accordance with procedures now well known in the art. Various cellulose derivatives known in the art may be employed in lieu of viscose. Cellulose derivatives include such derivatives as are produced by the cuprammonium process, and

other cellulosefest ers, such as celluloseacetate,

otherwise; defined-as an f aqueous dispersion of cellulose-sodium xanthate and cellulose.

1;As is known,.cellulose 'ethers may be held in solution i or dispersion in various "solvents; some iniorganic solventspand some in aqueous solvents, or in aqueouszalkali solutions.- A suitable solution of cellulose ether maybe used in the practice of the improved process, in lieu of a cellulose ester i solution,- if 1 desired. "Thorough impregnation of the fabric may be accomplished by i methods described in the present specification 15 aqueous alkali solution'ofcellulose ether (known in the art) be employed, the alkali will'be neutralized by the acid in the bath andthe cellulose etherwill ,betprecipitated in and on the fabric ofthetube. 'Where, as in the case of cellulose ethers,-simple precipitation will suflice, it may be desirable to employ in the precipitation bath the higher .acidity mentioned above:

, Of course, where cellulosederivatives, such as celluloseesters other thanviscose are used in the process, suitable regenerating agents are to be maybe employed, and,,may be de-esterified in,

any suitable known manner For example, this ester 1 may; ,be-hydrolyzed in any known: manner. The improvedprocess enables regenerated cellulose-coated fabric tubes composed of suitable vegetable fibres, to, be produced in an economical manner. Itais of especial importance that the invention enables regenerated-cellulose-coated tubes, to be produced by a continuous process which can be practiced-economically on a large scale with facility. By. providing the tube-drawing apparatus-with a battery of mandrels, form ing devices, coating, appliances, and means for handling a, plurality of tubes, a single attendant may take 'careof one or more machines having a capacityforlargeproduction. i

during the passage through the bath B". i In this portion of. the coursegof the tube, 3 the internal head of pressure furnished by the bath 1 is op-- posed to the external. head of pressure exertedby the externalbath. B. In fact; the level of the internal bath preferably is slightly above that of the external bath, so that danger of collapsing oi."

the .tubev is obviated. f

, As has been indicatedabove, when a cellulose derivative coating is appliedjto a paper tube, the

coating permeates the paper and tends to form ,a matrixwhich morestrongly ma'ts together the fibres 'of the paper. This is notably 'true where a viscosecoating is applied. So far as certain phases of the invention are concerned, it would be within thescope of the invention to manufacture the paper from a suitable paper pulp admixed with a cellulose derivative, such as viscose,

dry the paper, and thensubject it to the tubeforming and regenerating operations. The use of a very substantial amount of cellulose derivative is contemplated. It has been found highly satisfactory, for example; to apply, in the first described process, the-coating material in such quantity that the paper tubebearing the regenerated cellulose possesses aweight, afterdrying, which is on the orderof three times the weight of the paper employed in the process. 1

- Where thecellulose-derivative employedis, for example, cellulose acetate; it. is advisabletodry the paper after the cellulose acetate has been applied; and then pass-thepaperyafter thetube has been fornied, througha bath which will effect the regeneration, such as asuitable'alkali "bath. The operations of s'ubjectingthe tube, coated or permeated with cellulose acetate, to regeneratiori and subsequent purification, may be "similar to the methods already described in connection with the-preferred process.

While it is preferred topass the coated or permeated paper tube through a bath containedin a suitable tank, it will be appreciated by those skilledin the artthat it may be expedient; in some cases, to apply the regenerating medium,

or the coagulating and regenerating media, in-

other suitable-ways, such as by spraying operations, In the case ofviscose, it is known, of course, that regenerationcan be effected by applying heat, and such method may be resorted to for certain purposes, if desired.

integralregenerated cellulose tube reinforced by paper fibre, it being noted that the regenerated cellulose not only fills, all meshes and pores in the paper but also formsa continuous film or coating on the surface of the paper. Thorough permeation of the paper wi1l,of course, result in a coating, or coatings, on the papertube.

The foregoing detailed description is given for cleamess of understanding only, and no unnecessary limitations should be understood therefrom, but the appended claims should be construed as-broadly as permissiblein view of the priorart. H,

' What I regard as new and desire to secure by Letters Patent flpApparatus for forming coated tubes com prising: a precipitating bath tank; a tubular mandrel depending into said tank; tube-forming means associated with said mandrel; and means for drawinga'strip of fabric downwardly between said mandrel :andsaid tube-forming means and passing the tube progressively, as formed, through a precipitating bath in said tank, the tube havi The improved process provides, in effect, an

ing thereon a cellulose-derivative-coating,which is subjected to precipitating action in passing through said bath.

2.1Apparatus as specified claim 1, combined. with means for progressively applying acellulose:

derivative-coating to the iormed tube as it passes tosaidbath. 3,,Apparatus for forming cellulose-derivativecoated tube comprising; a precipitating bath tank; a tubular mandrel suspended above said,

tank and depending thereintopmeans for supporting a. fabric strip and shaping it into tubular form with overlapping longitudinal margins about said mandrel; means for effecting pasting together of said margins as the tubular strip passes to the bath; and means for drawing the, formed tube downwardly about said mandrel into .tened condition.

said tank is provided at its lower portion with about which said tube is drawn in flattened condition, and combined also with means extending through said mandrel for maintaining an internal liquid'head in-said tube above said guide.

6. Apparatus as specified in claim 3, in which the drawing means includes a guide roll for directing said tubeupwardly out of the precipitating bath.

'7. Apparatus as specified in claim 3, supplemented by a purifying bath and a guide roll for directing the tube upwardly out of themecipitating bath and guide-means for feedingit through the purifying bath.

8. Apparatus as specified in claim 3, combined with means for applying a cellulose derivative coating externally to the formed tube during its passage to the precipitating bath.

9. Apparatus as specified in claim 3, combined with means for applying a cellulose derivative coating internally to the formed tube during its passage to the precipitating bath.

10. Apparatus for manufacturing regeneratedcellulose-coated tubes comprising: a regenerating bath tank; a mandrel supported above said tank and depending thereinto; a transverse guide associated with the lower end of said mandrel about which the tube may be passed in flattened condition; meansfor supporting a fabric strip and forming it in tubular form about said mandrel as the strip moves toward said tank; means associated with said mandrel for pasting together the longitudinal margins of said strip progressively; a coating-applying device having an annular orifice presented to a surface of the formed tube; and means for feeding a cellulose derivative in measured quantity'through said coating-applying device.

11. In apparatus of the character set forth: a precipitating bath tank; a mandrel supported at a distance above said tank and depending thereinto; means for supporting a fabric strip at a point above the mandrel; a forming-ring encircling the mandrel at' a distance above the bath; a seam-paste-applying device above said forming-ring; a coating-applying device below said forming-ring for applying a cellulose derivative to the formed tube; a transverse guide in the lower portion of said tank; and means for drawing the formed tube in flattened condition about said guide and upwardly out of said tank.

12. Apparatus as specified in claim 11, combined witha purifying bath tank and means for feeding the tube therethrough subsequent to its emergence from the precipitating bath.

13. Apparatus as specified in claim 11, in which the seam-paste applying device comprises a nozzle' and an associated guide-member carried by the mandrel.

14. Apparatus as specified in claim 11, in which strip and keeping said margins separated until they have passed the nozzle.

15. Apparatus as specified in claim 11, in which the seam-paste applying device comprises a fixed guide-plate associated with the mandrel and an opposed adjustably mounted nozzle through which the paste passes.

16. Apparatus for manufacturing regeneratedcellulose-coated tubes, comprising: a regenerating bath tank; a tubular mandrel supported above said tank and depending thereinto; means for supporting a fabric strip and permitting it to descend into position about said mandrel; means associated with the mandrel for forming said strip into a tube and applying a cellulose derivative coating to said tube as the tube approaches the bath; a guide in the lower portion of said tank about which the tube may pass in flattened condition; means depending through said mandrel for maintaining an internal bath of predetermined head within the tube above said guide; and means for progressively feeding the tube and drawing the strip over the mandrel.

17. Apparatus as specified in claim 16, in which said mandrel has its lower end equipped with a depending member serving to gradually flatten the tube as it approaches said guide.

18. Apparatus for the manufacture of regenerated-cellulose-coated tubes comprising: a regenerating tank; a mandrel depending thereinto; means associated with said mandrel for forming a tube with overlapped longitudinal margins from a fabric strip drawn longitudinally over the mandrel; means for applying a cellulose derivative coating to said strip before it is formed into a tube; and means fordrawing the tube downwardly about said mandrel into the regenerating bath tank.-

19. Apparatus as specified in claim 18, combined with means for drying the coating applied to said strip before said strip reaches the mandrel.

20. Apparatus for forming reinforced seamless-matrix tubes, comprising: a precipitating bath, a mandrel depending into said bath; and means for feeding progressively downwardly over said mandrel and through said precipitating bath a paper tube thoroughly impregnated and coated with a solution of a cellulose derivative.

21. Apparatus for forming reinforced seamlessmatrix tubes, comprising: a precipitating bath; means for progressively forming a fabric strip into a tube and impregnating and coating the tube with a cellulose derivative solution; and means for progressively feeding the impregnated and coated tube through said precipitating bath.

22. Apparatus for making impregnated tubes,

comprising: a precipitating bath tank; a purifying bath tank; means for forming into tubing a cellulose-derivative-impregnated fabric strip;

and means for feeding said tubing progressively thrilgh precipitating and purifying baths in said tan 23. Apparatus as specified in claim 22, in which the forming means progressively curls a flat fabric strip into tbular form as said strip approaches the precipitating bath.

24. Apparatus as specified in claim 22, in which the forming means progressively curls a flat fabric strip into tubular form as said strip approaches the precipitating bath; and means is provided to coat the one face of the tubing progressively as it advances to said bath. 7

JOHN PAUL SMITH. 

